Method for purifying water.



J. ROCHE & A. OLIVER.

METHOD FOR PURIPYING WATER.

APPLICATION FILED AUGS, 1909.

Patented Mar. 22, 1910.

l Hi WI, 30% V [Q cyl/mwa JOHN ROCHE AND ALBERT OLIVER, OF NEW YORK, N. Y., ASSIGNORS, TO OLIVER-ROGHE COMPANY, 0F NEW YORK, N. Y., A CORPORATION 0F NEW YORK;

METHOD FOB PURIFYING WATER.

Specification of Letters Patent. Patented Mar. ,22, 1919.

Application ed. August 13, 1909. Serial No. 512,748.

To af-LZ whom it may concern:

Be it known that we, JOHN Booms and ALBERT OLIVER, citizens of the United States, said ROCHE being a resident of the borough of Manhattan, city, county, and State of New York, and said OLIVER being a resident of the borough of Brooklyn, county of Kings, city and State of New York, have invented a new and useful Method for Purifying lVater, of which the following is a specification.

This invention relates toimprovements in processes for purifying water for potable and industrial purposes, on a large scale, and particularly for the purification of the water supply of cities, factories and manufacturing plants, the same being accoml plished either with or without the introduction of a chemical coagulant according to the nature of thewater to be treated.

rlihe invention is described in detail in the accompanying specification, and the drawings forming part hereof, in which,

Figure l is a fragmentary, vertical sectional view of a unit of a filtration plant suitable for carryin out this process; and Fig'. 2 is a vertica sectional detail along line 2-2 of Fig. 1.

Referring tothe drawings, and the construction of the fil-tration plant shown therein, the reference letter A designates the filtration bed which is in communication with the conduit 8 in which water is maintained under uniform pressure. The inlet opening 9.-, connectingvsaid conduit and said bed, is provided with a perforate plate 10,'

the size of the openinff through which is adjusted to permit a ow of water under such. uniform pressure equivalent to the maximum working capacity of the bed when in clean or normal condition, and a cut-od valve 11, operable in any suitable way as by means of the rod 12, serves to cut off entirely the flow of water through said inlet when it is desiied to flush or clean the,

Such fiushing or sedimentation basin I3. cleaning is accomplished by opening suitable drainage pipes (not shown), thus drawing oif the im ounded Water below the filtration bed an inducing a reverse or down- Ward flow of the purified water standing above said bed. This cleansing operation may be repeated if desired toinsure cornp-lete cleansing of the bed, after which the 7 inches in thickness. A brass or copper screen 17 of relatively fine mesh, preferably 40 mesh to the linealinch., is superposed' above said carbon layer. Upon the screen 17 is arranged. a layer of fine sand 18,. preferably of the size to just refuse a screen of 30 mesh, and usually about 21 inches depth. In. order to prevent the flotation of the sand, particularly the upper portici-1 of the layer, and the consequent reduction in 'filtering efficiency, we provide means for loading said san-d, comprising a fine mesh copper screen 19- similar to the screen 17, upon which is placed a layer 20 of gravel about 8 inches in depth,V the particles of said layer being about one-half inch in diameter. By this means disruption, flotation or suspension of the sand layer, in case of accidental. increase in pressure in excess of the normal working pressure on the bed, is prevented, and disruption or disturbance of the sand by the creeping of currents upward along the side Walls is prevented by stag gering these walls as shown in the drawings.`

The several basins 13 in each of the respective filtration units are preferably subdivided by skeleton partition walls 2l, having arched open-ings 22 therein, whereby intercommunication is afforded between the several compartments of each unit, with the exception that the wall immediately adjacent vthe compartment constituting a standpi-pe, is imperforate, in order that all of the water entering through the inlet 9 must first pass through an apron screen C which is adapted to eliminate the larger impurities in suspension. rPhese screens are preferably constructed, as indicated in the drawings, in two seetions, an upper section 23 and a lower diameter, said layer being preferably about section 24, which are preferably hinged tol getlier as indicated by the numeral 25. A

cleat 26 and a girder 27 respectively serve of animal charcoal or coarse sand of approximately oneahalf inch in diameter. Said screens are tightly fitted intermediate the walls of two of the entering compartments so that all the water entering through the inlet 9 must pass therethrough. Obviously in those instances where the water is relatively ree from large impurities in suspension, these auxiliary screens may be elevated or dispensed with. In order that the screens may be elevated when it is desired to put them out of commission during the operation of cleansing or because of the relative reeness of the entering water from matters -in suspension, the 'lower members 24 are connected with rods 31 preferably having flexible upper ends consisting of light chains 32, which rods 31 are connected by lugs33 with a vrail 34 attached to the lower end of the section 24. The water, when purified by passage through the filtration beds is conducted otl through pipes 35 and conduit 36,.

the latter being preferabl super osed on the conduit 8, and separate there rom by the partition 37. The pressure of waterv upon the filtration bed, determined by the amount of flow through the inlet opening, is preferably such` as to establish a head of not less than 4 and not exceeding 24, when the bed is in a clean, normalcondition, de endent upon the thickness or depth of the ltering material.

To effectively'A preclude the passage of water .through the ltration bed without proper filtration of the same wev provide suitable steps u on the inclosing walls, whereby a Steppe or staggered ei'ect is produced. The lower step 44 supports a Stringer 45, which Stringer is level with the uppermost level of the inclined slats 14 and is adapted to receive the edges of the galva- 1 nized iron screen 15 the latter being secured thereto. A second step 46 supports a Stringer 47 upon 'which the copper screen 17 is positioned, said Stringer being level with the upper level of the carbon layer and athird step'48 is preferably arranged midway of the vsand layer in order that a portion of the sand will project beyond the outermost lim its of the sand supported by said screen 17 'the decomposition of the raw water, z'. e.

the electrolyte, will be accomplished, and a small but continuous supply of the products of electrolytic decomposition will be d-ischarged into the water as it passes through the bed. The exact amount of these products as determined from the actual operation of the apparatus, while relatively small is sufcient to Ymaintain the necessary biological action to accomplish the elimination of substantially all undesirable bacteria, and to maintain this action at full eiciency throughout the iltration. This biological purication is accomplished within the filter, instead of prior to the passage of the water therethrough,.in contradistinction to biological puriication in the scum which forms on the surface of a gravity filter.- Since ordinary ground water when interposed between zinc and co per electrodes will be decomposed by .5 vo t of "electricity, and also since the normal difference of potential between zinc and copper separated by an electrolyte consisting of lordinary ground water is .78 volts, it is evident that the means afforded in the above described apparatus arejample for the intended urpose of producing the small amount o the products of electrolytic decomposition required for such waters.

For the highest eiciency of purification it is requisite for the water to pass in a continuous and relatively slow upward flow Ithrough the layer of' carbon whichV has extensive superficial area and is capable of occliidingL substantial quantities of the nascentproducts resulting from the electrolysis of the water, whereby minute subdivisionv of the water is effected and intimate and prolonged contact with said products is secured. l

Having thus described our invention what we claim is:

The process of purifying water, which consists in inducing a relatively slow and lcontinuous iow of a body of water through` a filtering medium, consisting of porous particles of extensive superficial filtering area, said liltering medium bein interposed between a plurality of dissimi ar metallic elements and adording a resistance to the iow of' electric current therebetween in subiso resulting from the electrolytic decomposition thereof.

J OHN ROCHE. ALBERT OLIVER.

stantial excess of that of a metallic conductor, and serving to preclude the unimpeded flow of electric current between said electrodes, the said Water constituting the electrolyte of a rimary battery, whereby Witnesses: said water is sub]ected to intimate and pro- CLARENCE J. WYCKOFF, longed contact with the nascent products JOHN H. PYPER. 

